The present invention relates generally to agricultural machinery and, more particularly, to improvements to combine harvesters for agricultural crops.
The invention concerns a combine harvester having a mounted chopper which essentially comprises rotationally driven chopper blades and stationary counterblades cooperating therewith and which is equipped with a wide-distributor discharge for the chopped material.
The mounted chopper of a combine harvester is normally designed so that i) the mounted chopper can be operated to chop straw, or ii) it can be put into a position out of operation to deposit the straw in swathes. If the straw is chopped, a wide-distributor discharge is necessary because the cutting widths of combine harvesters can be up to 9 m. When the straw is chopped, the chopped material must be distributed over the field as evenly as possible across the entire cutting width of the combine harvester.
For this purpose German Patent 43 21 905 A1 proposes that the chopped material runs into two transfer funnels in order to introduce it into two impeller blowers. These impeller blowers are equipped with rotors which can be driven in rotation about vertical axes. Although the rotors are driven at relatively high speeds, this relatively elaborate measure is nonetheless insufficient. To try to ensure even discharge of the chopped material, the two ejection fittings are pivoted through an adjustable pivot angle. Of course it can be assumed that distribution is sufficiently even, however the structural elaborateness is extremely high. Moreover, a high drive output is necessary due to the high speed of the rotors for the impeller blowers.
A mounted chopper which consists of two chopper units is known from German Patent 42 18 235 A1. There the shafts carrying the chopper blades are arranged in the direction of travel of the combine harvester, so that the chopped material is ejected laterally, i.e. at an angle to the direction of travel. In another embodiment, the shaft carrying the chopper blades is arranged perpendicularly to the longitudinal axis or the direction of travel of the combine harvester. However, the direction of rotation is selected such that the separated chopped material is deposited between the rear wheels and the rear end of the combine harvester. In a modified embodiment the chopped material passes onto two impeller plates, as a result of which it is likewise discharged only laterally. In these embodiments it is impossible to have even distribution of the chopped material in combine harvesters with extremely wide cutting widths.
Starting from a state of the art known from German Patent 43 21 905 A1, it is an object of the invention to provide a mounted chopper whereby impeller blowers or like distributing means can be dispensed with.
Another object of the present invention is to provide an apparatus by which the chopped material is distributed evenly even with the widest cutting width of a combine harvester.